Hard disk drives with electrical connectors comprising a flexible circuit extending through an opening in the base and related methods

ABSTRACT

An improved hard disk drive of the invention comprises a housing, which comprises a base and a cover. The hard disk drive further internally comprises at least one disk for storage of data within the housing and an actuator for reading and recording of the data on the at least one disk. An electrical connector comprising a flexible circuit extends through an opening in the base and provides electrical contact between electronics external to the housing and one or more components within the hard disk drive. Methods for forming the improved hard disk drives are also disclosed.

BACKGROUND OF THE INVENTION

The present invention relates generally to hard disk drives withimproved electrical connectors and related methods.

A disk drive is a device used to store information in a computingenvironment. In a disk drive, data is generally recorded on planar,round, rotating surfaces (which are commonly referred to as disks,discs, or platters). There are several types of disk drives, includingoptical disk drives, floppy disk drives, and hard disk drives. Nowadays,hard disk drives tend to be most common. Strictly speaking, “drive”refers to a device distinct from its medium, such as a tape drive andits tape, or a floppy disk drive and its floppy disk. A hard disk drive(sometimes referred to as a HDD), also referred to as a hard drive, harddisk, or fixed disk drive, is a non-volatile storage device that storesdigitally encoded data on rapidly rotating platters with magneticsurfaces. Early hard disk drives had removable media; however, a HDDtoday is typically an encased unit with fixed media.

A typical hard disk drive includes a head disk assembly (HDA) and aprinted circuit board assembly (PCBA) attached to a disk drive base ofthe HDA. The HDA typically includes at least one magnetic disk, aspindle motor for rotating the disk, and a head stack assembly (HSA)having an actuator assembly with at least one transducer head, typicallyseveral, for reading and writing data from the disk. The PCBA includes aservo control system in the form of a disk controller for generatingservo control signals. The HSA is controllably positioned in response tothe generated servo control signals from the disk controller. In sodoing, the attached heads are moved relative to tracks disposed upon thedisk. The heads are typically distanced from the magnetic disk by agaseous cushion—so that they are said to “fly” over the disk. Thus, itis important that the position of the heads be well-controlled forproper reading and writing from the disk.

Hard disk drives are generally sealed to prevent dust and other externalsources of contamination from interfering with operation of the harddisk heads therein. Some hard disk drives are hermetically sealed. Ahermetic seal is generally understood to be an airtight seal. Note thatsome seals (e.g., those “sealing” air within the hard disk drive) arenot literally air tight, but rather utilize an extremely fine air filterin conjunction with air circulation inside the hard drive enclosure. Thespinning of the disks causes air to circulate therein, forcing anyparticulates to become trapped on the filter. The same air currents alsoact as a gas bearing, which enables the heads to float on a cushion ofair above the surfaces of the disks. However, “hermetically” sealedmeans that the seal is so airtight that the disk drive's internalpressure is substantially independent of the external or ambientpressure. This is in contrast to a conventional or non-hermeticallysealed disk drive that has a breather port with a filter in a wall ofthe base plate or cover for equalizing the disk drive's internalpressure with the external pressure. Thus, a hermetically sealed drivedoes not contain a breather port.

Within a hermetically sealed hard disk drive, gases other thanatmospheric air are often employed. Filling the sealed environment of ahard disk drive with gases other than air can enhance their performance.For example, use of lower density inert gases, such as helium, canreduce aerodynamic drag between the disks and their associatedread/write heads by a factor of approximately five-to-one as compared totheir operation in air. This reduced drag beneficially results inreduced power requirements for the spindle motor. A helium-filled drive,thus, uses substantially less power than a comparable hard disk driveoperating in an air environment. At the same time, the helium gas alsoconducts heat generated during operation of the disk drive away moreeffectively than air.

Hermetically sealed hard disk drives are first filled with a desiredgaseous medium (whether it be atmospheric air or one or more othergases) before operation. Then, if the constituency of the gaseous mediumsubstantially changes due to leakage of the hard disk drive housing, thehard disk drive must be either discarded or refilled with the desiredgaseous medium. Filling disk drives to a desired pressure andconcentration of gaseous components, however, can be both time-consumingand difficult. A number of patent documents focus on providing and/orreplenishing gases such as helium at a desired concentration within ahard disk drive. See, for example, U.S. Patent Publication Nos.2003/0081349 and 2003/0089417. Also see U.S. Pat. No. 6,560,064.

Due to imperfect sealing of hard disk drive housings, the benefits ofusing lower density gases such as helium are conventionally notlongstanding. Potential paths of gas leakage (allowing both air flowinto the hard disk drive housing and allowing gas outflow from the harddisk drive housing) are throughout the hard disk drive. Those potentialpaths of gas leakage include those associated with the junction of twomating components thereof. Those components include, for example, screwsor other mechanical fasteners used to conventionally fasten multipleparts of the housing together. A further potential path of gas leakageis associated with the electrical connector and its exit from the harddisk drive housing. In addition, gasket seals and the like used toimprove the seal between multiple components are often susceptible to atleast some leakage. As gas, such as helium, leaks out of a sealed harddisk drive, air leaks in (or vice versa), causing undesirable effects inthe operation of the disk drives—even possibly causing the disk drivesto catastrophically fail. For example, an increased concentration of airinside the hard disk drive may increase forces on the read/write headtherein due to turbulent airflow within the drive. Further, suchundesired air may cause the read/write heads to “fly” at too great adistance above the disks. The risk of unexpected failure due toinadequate concentration of helium within such drives is a considerabledrawback to helium-filled disk drives, particularly since the datastored within the disk drive can be irretrievably lost if the disk drivefails.

Elimination of or minimization of leakage is desired for not only bettercontainment of gas within a hard disk drive, but for other reasons aswell. One such reason relates to a reduction of complications arisingfrom electromagnetic interference. Electromagnetic interference (“EMI,”also called radio frequency interference or “RFI”) is a usuallyundesirable disturbance caused in an electrical circuit byelectromagnetic radiation emitted from an external source. Suchdisturbance may interrupt, obstruct, or otherwise degrade or limit theeffective performance of the circuit. EMI can be induced intentionallyfor radio jamming, as in some forms of electronic warfare, orunintentionally, as a result of spurious emissions and responses,intermodulation products, and the like. A source of EMI may be anyobject, artificial or natural, that carries rapidly changing electricalcurrents, such as another electrical circuit or even the sun or NorthernLights. Broadcast transmitters, two-way radio transmitters, pagingtransmitters, and cable television are also potential sources of EMIwithin residential and commercial environments. Other potential sourcesof EMI include a wide variety of common household devices, such asdoorbell transformers, toaster ovens, electric blankets, ultrasonic pestcontrols (e.g., bug zappers), heating pads, and touch-controlled lamps.It is known that EMI frequently affects the reception of AM radio inurban areas. It can also affect cell phone, FM radio, and televisionreception, although to a lesser extent. EMI can similarly affectperformance of a computer.

In conventional hard disk drives, as with potential paths of gasleakage, unwanted and potentially problematic EMI wavelengths can entera disk drive through a number of places. Within integrated circuits, themost important means of reducing EMI are: the use of bypass or“decoupling” capacitors on each active device (connected across thepower supply and as close to the device as possible), risetime controlof high-speed signals using series resistors, and VCC filtering. If allof these measures still leave too much EMI, shielding such as usingradio frequency (RF) gasket seals (which are often very expensive) andcopper tape has been employed. Another method of reducing EMI is via useof metal hard disk drive components. While the use of metal componentsundesirably increases the overall weight of an apparatus, use of metalcomponents has been conventionally mandated in the hard disk driveindustry due to the EMI sensitivity of mechanical spinning componentstherein. Without mechanical spinning components therein, however,manufacturers of flash drives have taken advantage of the benefits of,for example, a plastic case for enclosure of the drive. See, forexample, U.S. Pat. No. 7,301,776, which describes how metal materialused for top and bottom plates of the drives described therein can bereplaced by plastic as there are fewer EMI issues associated with flashmemory devices as compared to mechanical spinning hard disk drives.

As discussed in U.S. Patent Publication No. 2003/0179489, despite theadvantages of helium-filled drives, such drives have not beencommercially successful. This is mainly due to problems associated withleakage of gas from within the drives over time. Unlike air-filled diskdrives, helium-filled drives do not include a filtered port to equalizethe pressure within the drive to the ambient pressure—which ensuingpressure differential contributes to increased leakage of gas. Thus,while prior art helium drives are completely “sealed” in theconventional sense, it is still possible for helium gas therein to leakout past conventional rubber gasket seals used to seal the top cover tothe drive base. Such leakage is not surprising given the relativelysmaller size (i.e., lower atomic weight) of the helium atoms incomparison to the constituent gases found in air (i.e., nitrogen andoxygen). That is, the rubber gasket seals on prior art drives allow therelatively smaller helium atoms to diffuse through the rubber membrane.Indeed, such prior art gasket seals do not provide hermetic seals withrespect to air (i.e., the gasket seals are also permeable to the largeratoms of nitrogen and oxygen in air) since it is air that typicallydisplaces the helium gas that leaks from the drive.

Most prior art gasket seals are only intended to keep relatively largecontaminants such as dust or smoke from the interior of a disk drive.However, such gasket seals are preferred as compared to other, morepermanent methods of sealing a drive for two main reasons. First, suchseals typically do not outgas and, thus, do not contribute to thecontamination of the interior of the drive. Secondly, such seals may bereused if necessary during the assembly of the disk drive, such as whenan assembled drive fails to pass certification testing and must be“re-worked.” Re-working a drive typically entails removing the top coverfrom the base and replacing a defective disk or read/write head whilethe drive is still in a clean room environment. The re-worked drive isthen reassembled, which can even be done using the same rubber gasketseal positioned between the base and the top cover. Unfortunately,however, while such gasket seals are convenient, they simply often donot provide a sufficient hermetic seal to maintain the requiredconcentration of helium (or other low density gas) within the disk drivefor the desired service life of the drive.

In view of the potential for long-term performance problems, U.S. PatentPublication No. 2003/0179489 describes a disk drive assembly having asealed housing. As described therein, a disc drive includes a base platesupporting a spindle motor and an actuator assembly. A structural coveris removably attached to the base plate to form an internal environmentwithin the disc drive. The internal environment of the drive is filledwith a low density gas such as helium, and a sealing cover ispermanently attached to the base plate and the structural cover to forma hermetic seal that maintains a predetermined concentration of the lowdensity gas within the internal environment over a service lifetime ofthe disc drive.

The disc drive further includes a first seal secured between the baseplate and the structural cover to prevent contaminants from entering theinternal environment of the disc drive. The first seal is formed from amaterial such as rubber that allows leakage of the low density gas fromthe internal environment at a sufficiently low rate so that the discdrive may be operated for a predetermined period of time in the absenceof the sealing cover.

In one embodiment, the base plate includes a raised outer edge and thesealing cover includes a downward depending edge that is adhesivelybonded within a groove formed between an outer surface of the structuralcover and the raised outer edge of the base plate. Alternatively, thesealing cover may include a downward depending edge that is adhesivelysecured to an outer perimeter wall of the base plate. In an alternativeembodiment, the sealing cover is soldered to a top surface of the raisedouter edge of the base plate. Such assemblies purportedly create ahermetic seal that will maintain desired concentrations of helium (orother low density gases) within the drive over the operational lifespanof the drive (e.g., leaking helium at such a low rate that it would takeover seventy years for the helium concentration to drop below apredetermined lower limit). However, such sealing covers are not withouttheir limitations—e.g., those dimensional limitations discussed in U.S.Patent Publication No. 2003/0179489 and the potential interference ofsuch sealing covers with electrical connectors, such as those associatedwith flex circuitry protruding from the disk drive. Thus, improvementsare still needed.

In addition, while U.S. Patent Publication No. 2003/0223148(corresponding to U.S. Pat. No. 7,119,984) discusses improvedcontainment of helium within a hard disk drive, the methods therein relyon laser-based metal sealing of such drives. Further, such “sealing” ofdrives is incomplete in that it does not prevent leakage through valvesand ports used to inject gas into disk drive housings once sealed assuch. As described therein, a base can be combined with a cover byoverlapping respectively corresponding coupling flanges of the base andcover with each other. The coupling flanges are then described as beingjointed and fastened together by spot welding, but only if both of thebase and cover are made of metal including iron. Alternatively, hermeticsealing to some extent is said to be guaranteed if seam-welding iseffected by continuously carrying out spot welding. Alternatively, whenthe base and the cover are made of a metal other than iron or a resinmaterial, the coupling flanges are described as being joined together bymeans such as wrap-seaming, screws, or riveting. Still further, if boththe base and cover are made of metal including aluminum or made of aresin material, the coupling flanges are stated to be preferably jointedand fastened together by screws or rivets. Further, in the outerperipheral portion of the jointed coupling flanges, a frame composed ofa pair of L-shaped frame elements can be attached to force the jointedcoupling flanges to be closed up tightly. Each of these L-shaped frameelements are made of so-called engineering plastic, e.g., polyamideresin or polyphenylene sulfide resin, and have a sectional form with arecess corresponding to the outer shape of the jointed coupling flanges.In this case, the L-shaped frame elements are fixed to the jointedcoupling flanges of the housing by adhesive or by welding the frameelements per se. Also see U.S. Pat. No. 6,762,909 for a description oflaser welding of a disk drive's cover and base plate made of aluminum orother alloys. Similarly, U.S. Pat. No. 5,608,592 discusses how spotwelding can be used to secure a base and cover of a disk drive housing.

U.S. Pat. No. 4,686,592 discloses a housing comprising a lower bodyportion and a cover portion. Lower body portion is stated to becylindrical in shape, having a lip located towards the outer peripheryand a ledge associated therewith. Cover portion is stated to have a lipportion along its outer periphery. The inner and outer diameter of thelips are selected so that the two lips nest with one another when thecover portion is placed over the lower body portion, i.e., the outerdiameter of the lower body portion's lip is selected to be greater thanthe inner diameter of the cover portion's lip. Further, the height ofthe cover portion's lip is selected with respect to the height of thelower body portion's lip so that a groove is formed for accommodatingthe outer periphery of the disk. Adhesives, such as epoxy, can beapplied in the groove to assist in fixedly securing the disk within thegroove. The disk is further secured in the groove by the clamping actionprovided by the cover portion and the lower body portion. Alternativemethods for securing the cover portion to the lower body portiondescribed therein include: threading, cam-locking, radial crimping,laser welding, ultrasonic welding, and the like.

U.S. Pat. Nos. 6,392,838 and 6,525,899 disclose a disk drive assemblypurportedly hermetically encased within a metallic can. The metallic cancomprises a top and bottom housing. Each housing component includes asealing flange extending around its periphery. After the disk driveassembly is securely placed into the bottom housing, the top and bottomhousings are mated and sealed together by forming a seam seal with theseal flanges. Also disclosed is use of a metallic gasket seal having aC-shaped cross-sectional area to purportedly hermetically seal a diskdrive assembly. The C-seal includes a base layer and a plating layer,with the length of the seal extending the periphery of the disk drivebase, similar to conventional elastomer gasket seals. After the diskdrive cover is placed over the disk drive base and C-seal, the cover isclamped, thus compressing the C-seal. The resulting compression forcesthe plating layer to fill surface asperities in the area of the diskdrive cover and base that contact the C-seal. These configurationspurportedly provide assemblies with atmosphere leak rates of less thanone cubic centimeter per 10⁸ seconds or 5% of the volume of the sealedatmosphere over ten years.

No matter how a hard disk drive is individually configured and sealed,it must be configured to electrically couple with external components ina computing environment. As described in U.S. Pat. No. 5,454,157,information is transferred to and from drive platters within a diskdrive through the magnetic read/write heads by way of flexcircuits thatcouple to the drive heads. Special flexible flexcircuits also couple theactuator arm in order to control the movement of this arm and theassociated magnetic read/write heads. These flexcircuits must be able tocouple to the read/write heads, the actuator arm movement device, and tothe platter spin motor, which are all situated inside the sealedchamber. The other ends of these flexcircuits must be able to connect tothe outside of the sealed chamber to a disk drive controller circuit ona PC board.

A typical prior art disk drive 110 is shown in FIG. 1. A base 101 isshown for providing a mounting surface for the actuator arm, theplatters, and other drive mechanisms. Case 100 is placed over the base101, the platters (not shown), and the actuator arm (not shown) in orderto provide the sealed chamber. As is conventional, flexcircuits andconnectors 103 and 102 are shown extending from the junction of thesealed chamber. The free ends of the connectors are exposed outside ofthe sealed chamber and the other ends are coupled within the chamber tothe actuator arm movement, the read/write heads, and the platter spinmotor (actuator). The cables 102 and 103 are standard flexibleconnectors and hook inside under the base 101 in order to connect toreceiving connectors of a PC board located and mounted under the base101 and acting as a hardware controller device. The flexcircuits 102 and103 are placed through the junction of the base 101 and the case 100. Inorder to maintain the sealed chamber with these flexcircuits present inthis junction, the junction of the case 100 and the base 101 aretypically epoxy- or glue-sealed. The sealant flows around theirregularly shaped cables to insure a proper chamber. However, once thebase 101 and the case 100 are sealed by epoxy, glue, or cement, they arepermanently affixed together. This makes repair of the componentslocated within the chamber problematic. Also, as the flexcircuits 102and 103 outwardly extend from the disk drive unit, they often tear andrip if caught during manufacturing on an assembly line, which candestroy the entire hard disk drive.

In view of the number of potential problems impacting effective andlong-term performance of hard disk drives, alternative methods andapparatus for improved hard disk drives are desired. Particularlydesired are alternative methods and apparatus for providing efficientelectrical connection between hard disk drives and external components,where such connection facilitates improved hermetic sealing of hard diskdrives.

SUMMARY OF THE INVENTION

An improved hard disk drive of the invention comprises a housing, whichcomprises a base and a cover. The hard disk drive further internallycomprises at least one disk for storage of data within the housing andan actuator for reading and recording of the data on the at least onedisk. An electrical connector comprising a flexible circuit extendsthrough an opening in the base and provides electrical contact betweenelectronics external to the housing and one or more components withinthe hard disk drive. While more than one flexible circuit may exit thehard disk drive, the flexible circuit extending through an opening inthe base is an actuator flex cable in an exemplary embodiment. As such,electrical contact between the electronics external to the housing andan actuator within the hard disk drive facilitates reading and recordingof the data at any desired location on the at least one disk within thehard disk drive.

In one embodiment, the flexible circuit is embedded within the base ofthe hard disk drive. In an exemplary embodiment, the base comprisesplastic. The flexible circuit can be embedded within the base byovermolding the plastic base around the flexible circuit.

Further advantages are obtained when the embedded flexible circuitcomprises a tortuous path through the base. In one embodiment, theembedded flexible circuit comprises a labyrinth path through the base.In another embodiment, the embedded flexible circuit comprises aserpentine path through the base. The more tortuous the path, the morethat changes of direction will occur throughout the path. In oneembodiment, the embedded flexible circuit changes direction at leastabout three times. In another embodiment, the embedded flexible circuitchanges direction at least about five times. In yet another embodiment,the embedded flexible circuit changes direction at least about seventimes.

Further advantages can also be obtained when the opening within the baseis non-linear. In one embodiment, position of a first end of the openingon the exterior of the hard disk drive is offset from position of asecond end of the opening on the interior of the hard disk drive.According to a further embodiment, the opening extends essentiallytransversely from an exterior of the hard disk drive to approximately amidpoint of the base in an essentially linear manner, at which point theopening changes direction, extending essentially longitudinally withinthe base before changing direction and exiting the base essentiallytransversely toward an interior of the hard disk drive.

Methods for forming the improved hard disk drives are also disclosed. Amethod of forming an improved hard disk drive of the invention comprisessteps of: providing the cover for the housing; providing the base forthe housing; providing the electrical connector comprising the flexiblecircuit; positioning the flexible circuit within the opening of thebase; enclosing the cover and the base around components internal to thehard disk drive; sealing the opening around the flexible circuit; and,optionally, evacuating and filling the hard disk drive with a desiredgaseous medium when the desired gaseous medium is other than atmosphericair.

According to a further embodiment, the method comprises the step ofembedding the flexible circuit within the base. In one variation of thisembodiment, the flexible circuit is embedded between two adjacent layerswithin the base. In another variation of this embodiment, the flexiblecircuit is embedded within a single layer of the base. For example, theflexible circuit is overmolded within the base during molding of thebase in one embodiment, such as when the base comprises plastic.

BRIEF DESCRIPTION OF THE DRAWINGS

Note that the components and features illustrated in all figuresthroughout this application are not necessarily drawn to scale and areunderstood to be variable in relative size and placement. Similarly,orientation of many of the components and features within the figurescan vary such that, for example, a horizontal configuration could bereadily reoriented to a vertical configuration, and vice versa, asdesired.

FIG. 1 is a perspective view of a prior art hard disk drive showingflexcircuits exiting the hard disk drive at the junction of the base andcover of the hard disk drive housing.

FIG. 2 is a partial perspective view of a prior art hard disk drive withthe top cover of the drive housing removed to illustrate certainfeatures.

FIG. 3A is a top perspective view of a hard disk drive comprising anelectrical connector comprising a flexible circuit extending through anopening in the base.

FIG. 3B is a partial phantom top perspective view of the hard disk driveof FIG. 3A, illustrating an exemplary electrical connector thereof.

FIG. 3C is a partial cross-sectional view of the hard disk drive of FIG.3B, taken proximate exit of the electrical connector from the hard diskdrive along plane C-C of FIG. 3B.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

The present invention is beneficially applied in conjunction with anysuitable conventional hard disk drive in need of performanceimprovements. According to the present invention, an electricalconnector comprising a flexible circuit extends through an opening inthe base and provides electrical contact between electronics external tothe housing and one or more components (e.g., an actuator) within thehard disk drive. Thus, unlike conventional hard disk drives, flexiblecircuits are removed from and do not disrupt the sealed interfacebetween housing components. Due to the often complicated configurationsused to adequately seal the housing components together, removing theelectrical connector from the interface between the base and the coverof conventional hard disk drive housings is advantageous in that itfacilitates greater design flexibility and more effective hermeticsealing of hard disk drives. Further, preferred embodiments of theinvention minimize potential paths for leakage of gas andelectromagnetic interference (EMI) within the electrical connectoritself.

A disk drive assembly conventionally includes a base to which variouscomponents of the disk drive are mounted. A top cover cooperates withthe base to form a housing that defines an encased environment for thedisk drive. Any disk drive comprises any of a number of suitablecomponents encased within the housing. The components within the diskdrive include, for example, a spindle motor, which rotates one or moremagnetic disks at a constant high speed, and an actuator assembly forwriting information to and reading information from circular tracks onthe disks. The actuator assembly typically includes a plurality ofactuator arms extending towards the disks, with one or more flexuresextending from each of the actuator arms. Mounted at the distal end ofeach of the flexures is a read/write head, which includes an air bearingslider enabling the head to fly in close proximity above thecorresponding surface of the associated disk during operation of thedisk drive. When the disk drive is powered down, the heads may be movedto a landing zone at an innermost region of the disks where the airbearing sliders are allowed to land on the disk surface as the disksstop rotating. Alternatively, the actuator assembly may move (unload)the heads beyond the outer circumference of the disks so that the headsare supported away from the disk surface by a load/unload ramp when thedrive is powered down.

Turning now to the drawings, there is shown in FIG. 2 part of a priorart hard disk drive 216. The prior art hard disk drive 216 illustratedin FIG. 2 is only one example of many well-known embodiments of harddisk drives and is illustrated to show exemplary components of hard diskdrives for use as a reference in conjunction with a description of thepresent invention. Recognize, however, that many conventional hard diskdrives can be modified according to the improvements of the invention.

As shown in FIG. 2, a conventional hard disk drive 216 has a rigid outerhousing including a base 218 and a cover 220. In FIG. 2, the cover 220is removed from the base 218 to reveal a disk pack or spindle assembly222 and a rotary actuator 224, both of which are mounted movably withrespect to the housing formed by the base 218 and cover 220. Moreparticularly, the spindle assembly 222 includes a top disk 226 andseveral additional concentrically stacked and spaced-apart disksrotatable about a vertical spindle axis 228.

Rotary actuator 224 includes an actuator shaft 230 mounted to pivotrelative to the base 218 about a vertical actuator axis 232. Severaltransducer support arms, including a top support arm 234, are fixed torotate with the actuator shaft 230. Each arm carries a magnetic datatransducing head—e.g., a transducing head 236 on a support arm 234. Therotary actuator 224 pivots to move the transducing head 236 alongarcuate paths generally radially with respect to the disks. Selectiveactuator 224 pivoting, in combination with controlled rotation of thedisks, allows reading and recording of data at any desired location atany one of the disk recording surfaces. Rotary actuator 224 is pivotedby selective application of an electrical current to a voice coil 238supported for arcuate movement within a magnetic field created by apermanent magnet arrangement 240, which includes several magnets and apoll piece (both of which are not illustrated in further detail).

The rotary actuator 224 and spindle assembly 222 are supported betweentwo opposed housing walls, including a top wall 242 of the cover 220 anda bottom wall of the base 218. Spindle shaft 244 and the actuator shaft230 may be stationary—meaning that they are integral with thehousing—with the disks and support arms being mounted to rotate relativeto their respective shafts.

The cover 220 includes a vertical continuous sidewall structureincluding a rearward wall 286, a sidewall 288, and a forward wall 290.Here, the upper sidewall structure includes a generally flat, horizontalcontinuous bottom edge 292, though some embodiments may include a flangeor other mated fitting so as to fit into a top edge 200 of base 218facilitating a tight fit and/or laser-welding. The base 218 includes anupright wall structure including a forward wall 294, a rearward wall296, and two opposed sidewalls, one of which is shown at 298. Thesewalls combine to form a continuous, horizontal top edge 200. FIG. 2 alsoillustrates an elastomeric gasket seal 202 mounted to top edge 200 ofthe base 218. When the cover 220 is assembled onto the base 218, theconfronting bottom edge 292 of the cover 220 and the top edge 200 of thebase 218 are brought into sealing engagement to close the housing aboutthe spindle assembly 222 and the rotary actuator 224.

The upper and lower sidewalls 288, 298 are generally relatively thick tolend rigidity to the housing. The top wall 242 of the cover 220 may beformed with a horizontal full height region 204 and a horizontalrecessed region 206, the two types of regions being interconnected byseveral non-horizontal regions as indicated at 208, 210 and 212. Oneportion of the full height region 204 accommodates the rotary actuator224 and the spindle assembly 222. The non-horizontal regions 208, 210,212 provide additional stiffness to the top wall 242 of the cover 220,which strengthens the top wall 242 and enables a somewhat reducedthickness wall construction.

According to one embodiment of the invention illustrated in FIGS. 3A-3C,an improved hard disk drive 302 of the invention comprises an electricalconnector comprising a flexible circuit 304 exiting the hard disk drive302 from an opening 312 within a base 308 of the hard disk drivehousing. The base 308 and cover 310 mate to form an enclosed housing forcontainment of internal hard disk drive components and containment ofany gaseous medium filled therein.

The flexible circuit 304 typically comprises a plurality of electricalconductors encapsulated within an insulating material. The flexiblecircuit 304 facilitates connection of the hard disk drive 302 toexternal electrical components. As compared to rigid pin connectorsconventionally extending from the base of hard disk drives, use of aflexible circuit 304 for the electrical connector provides moreflexibility in design and assembly of components as it has built-intolerance when used for connecting adjacent components. Further,flexible circuits are generally not subject to precise alignmentrequirements associated with rigid electrical connectors.

The flexible circuit 304 may perform any needed electrical connection.Further, more than one flexible circuit 304 may exit the hard disk drive302. Preferably, when more than one flexible circuit 304 exits the harddisk drive 302, each flexible circuit 304 exits the hard disk drive 302from an opening 312 within the base 308 according to the presentinvention.

In an exemplary embodiment, the flexible circuit 304 comprises anactuator flex cable that carries electrical signal to and from theactuator of the hard disk drive 302. The actuator flex cable provideselectrical contact between electronics external to the housing and theactuator within the hard disk drive 302, which is supported on bearingsallowing radial motion of the actuator about its pivot point. The radialmotion of the actuator allows the read/write transducers supported onsuspensions fixed to the actuator to access data tracks on the disksurfaces located at any radial position from the inside diameter of thedisk to the outside diameter of the disk.

According to a further embodiment, the flexible circuit 304 is embeddedwithin the base 308 to form a tortuous path 306 as illustrated in, forexample, FIG. 3B. According to this embodiment, the flexible circuit 304is embedded within the base 308 of the hard disk drive 302. Preferably,when embedded as such, the flexible circuit 304 is positioned therein ina tortuous path 306 to maximize changes of direction (e.g., direction ofcurvature) within the embedded section of the base 308.

The more tortuous the path, the more changes of direction will occurtherein. In one embodiment, the flexible circuit 304 of the inventionchanges direction at least about three times within the tortuous path306. In a further embodiment, the flexible circuit 304 changes directionat least about five times within the tortuous path 306. In yet a furtherembodiment, the flexible circuit 304 changes direction at least aboutseven times within the tortuous path 306. As such, the embedded flexiblecircuit 304 comprises a serpentine or labyrinth path through the base308 according to an exemplary embodiment. By embedding the flexiblecircuit 304 within a plastic base 308 as such, the likelihood that thepath of such a flexible circuit 304 as it exits the hard disk drive 302will serve as an effective path for leakage of a contained gaseousmedium and/or entry of problematic electromagnetic waves is furtherminimized. Inclusion of such a tortuous path 306 was also found tominimize leakage through the electrical connector itself as compared toelectrical connectors associated with conventional configurations ofelectrical connectors (i.e., both flexible circuits and rigid pinconnectors) exiting hard disk drives, which have relatively unobstructedlinear paths.

As illustrated in FIG. 3C, a flexible circuit 304 of the invention exitsthe hard disk drive 302 through an opening 312 within the base 308. Inan exemplary embodiment, the opening 312 within the base 308 isnon-linear. That is, the opening 312 does not linearly extend throughthe base 308 between the interior and exterior of the hard disk drive302. Rather, position of a first end of the opening 312 on the exteriorof the hard disk drive 302 is offset from position of a second end ofthe opening 312 on the interior of the hard disk drive 302. In anexemplary embodiment, the opening 312 extends essentially transverselyfrom the exterior of the hard disk drive 302 to approximately a midpointof the base 308 in an essentially linear manner, at which point theopening 312 changes direction, extending essentially longitudinallywithin the base 308 before changing direction and exiting the base 308essentially transversely toward the interior of the hard disk drive 302.

According to this embodiment, the flexible circuit 304 is embeddedwithin the base 308 using any suitable methodology. Methods forembedding the flexible circuit 304 within the base 308 vary dependingon, for example, the material from which the base 308 is fabricated.

In one embodiment, the base 308 comprises multiple layers, with theflexible circuit 304 being embedded between two adjacent layers withinthe base 308 by fastening the layers around the flexible circuit 304using any suitable fastening mechanism. For example, the flexiblecircuit 308 can be positioned on one metal layer forming the base 308,after which time a second metal layer forming the base 308 is securelypositioned thereon to form a sandwich structure with the flexiblecircuit 304 embedded between two metal layers of the base 308.

In another embodiment, the flexible circuit 304 is embedded within asingle layer of the base 308. For example, when the base 308 comprises aplastic material, the flexible circuit 304 can be overmolded within thebase 308 during injection—or other molding of the base 308. Suitablemolding techniques are known to those of ordinary skill in the art.

During the process of enclosing the cover 310 and base 308 around theinternal components, any suitable sealing material 321 may be positionedbetween the cover 310 and the base 308, such as shown in FIG. 3C, forsealing engagement of the hard disk drive housing in an exemplaryembodiment. For example, conventional rubber gasket seals or othersealing materials 321 such as irradiation-crosslinked, closed-cell foam(e.g., that commercially available under the VOLARA tradedesignation—Sekisui Voltek of Lawrence, Mass.) can be used for such aseal.

After enclosing the base 308 and the cover 310 of the hard disk drivehousing, with the flexible circuit 304 exiting the hard disk drive 302through an opening 312 in the base 308, the opening 312 through whichthe flexible circuit 304 exits the hard disk drive 302 is sealed. Anysuitable method may be used for sealing the opening 312. In oneembodiment, the opening 312 surrounding the flexible circuit 304 isfilled with a potting compound (e.g., an epoxy potting compound such asentrochem 318, available from entrochem, inc. of Columbus, Ohio).

In one embodiment, the base 308 and the cover 310 of the hard disk drivehousing are assembled around components internal to the hard disk drive302 in an environment filled with the desired gaseous medium (when thedesired medium is other than atmospheric air). In another embodiment,after enclosing the base 308 and the cover 310 around internalcomponents to the hard disk drive 302 and temporarily sealing the harddisk drive housing using any suitable methodology as known to thoseskilled in the art, the hard disk drive 302 is evacuated and filled withthe desired gaseous medium (when the desired medium is other thanatmospheric air). A fill port or other conventional methodology can beused for filling the disk drive with the desired gaseous medium usingany suitable methodology as known to those skilled in the art accordingto this embodiment. The hard disk drive 302 then preferably undergoesroutine testing and re-working, if necessary. Advantageously, inpreferred embodiments, the flexible circuit 304 need not generally beremoved and/or resealed within the opening 312 in the base 308 whenre-working the hard disk drive 302. Once the hard disk drive 302 passessuch testing, the hard disk drive 302 may be further hermetically sealedusing any suitable method.

Advantages associated with hard disk drives and related methods of thepresent invention include, for example, improved shielding from EMI aswell as improved containment of a gaseous medium within an enclosed harddisk drive. Within the sealed environment of hard disk drives of theinvention, a gas having a density less than that of atmospheric air canbe effectively employed. For example, a gaseous medium comprising atleast one of nitrogen, helium, or other noble gases can be employedtherein, alone or in combination with one or more of each other and/orair. In an exemplary embodiment, an improved hard disk drive of theinvention is capable of providing and maintaining an adequate sealedenvironment for at least five years. An adequate sealed environment isone in which hard disk drive performance is not significantly affecteddue to leakage. According to one embodiment, at least about 90% byvolume, preferably at least about 95% by volume, of a gaseous mediumoriginally contained within a hard disk drive remains after five years.Any suitable methodology can be used to detect leakage of a gaseousmedium from a hard disk drive and amounts thereof.

Various modifications and alterations of the invention will becomeapparent to those skilled in the art without departing from the spiritand scope of the invention, which is defined by the accompanying claims.It should be noted that steps recited in any method claims below do notnecessarily need to be performed in the order that they are recited.Those of ordinary skill in the art will recognize variations inperforming the steps from the order in which they are recited. Further,while the present invention has been described with respect to a harddisk drive, it should be understood that the present invention alsofinds utility in other data storage devices—e.g., optical andmagneto-optical storage devices.

The invention claimed is:
 1. A hard disk drive, comprising: a housingcomprising a base and a cover; at least one disk for storage of datawithin the housing; an actuator for reading and recording of the data onthe at least one disk; and an electrical connector comprising a flexiblecircuit embedded within the base of the hard disk drive and flexiblyextending through an opening in the base and providing electricalcontact between electronics external to the housing and one or morecomponents within the hard disk drive.
 2. The hard disk drive of claim1, wherein the flexible circuit is embedded within a single layer of thebase of the hard disk drive.
 3. The hard disk drive of claim 1, whereinthe base comprises plastic.
 4. The hard disk drive of claim 1, whereinthe embedded flexible circuit changes direction at least about threetimes.
 5. The hard disk drive of claim 1, wherein the embedded flexiblecircuit changes direction at least about five times.
 6. The hard diskdrive of claim 1, wherein the embedded flexible circuit changesdirection at least about seven times.
 7. The hard disk drive of claim 1,wherein the flexible circuit comprises an actuator flex cable.
 8. Thehard disk drive of claim 1, wherein the opening within the base isnon-linear such that a first end of the opening on an exterior of thehard disk drive is offset from position of a second end of the openingon an interior of the hard disk drive.
 9. The hard disk drive of claim1, wherein a position of a first end of the opening on the exterior ofthe hard disk drive is offset from a position of a second end of theopening on the interior of the hard disk drive.
 10. A hard disk drive,comprising: a housing comprising a base and a cover; at least one diskfor storage of data within the housing; an actuator for reading andrecording of the data on the at least one disk; and an electricalconnector comprising a flexible circuit embedded within and extendingthrough an opening in the base and providing electrical contact betweenelectronics external to the housing and one or more components withinthe hard disk drive, wherein the embedded flexible circuit comprises atortuous path through the base.
 11. A method of forming the hard diskdrive of claim 10, comprising steps of: providing the cover for thehousing; providing the base for the housing; providing the electricalconnector comprising the flexible circuit; positioning the flexiblecircuit within the opening of the base; enclosing the cover and the basearound components internal to the hard disk drive; and sealing theopening around the flexible circuit.
 12. The method of claim 11,comprising the step of embedding the flexible circuit within the base.13. The method of claim 12, wherein the flexible circuit is embeddedbetween two adjacent layers within the base.
 14. The method of claim 12,wherein the flexible circuit is embedded within a single layer of thebase.
 15. The method of claim 14, wherein the flexible circuit isovermolded within the base during molding of the base.
 16. The method ofclaim 11, wherein the base comprises plastic.
 17. A hard disk drive,comprising: a housing comprising a base and a cover, wherein the basecomprises plastic; at least one disk for storage of data within thehousing; an actuator for reading and recording of the data on the atleast one disk; and an electrical connector comprising a flexiblecircuit embedded within and extending through an opening in the base andproviding electrical contact between electronics external to the housingand one or more components within the hard disk drive, wherein theflexible circuit is embedded within the base by overmolding the plasticbase around the flexible circuit.
 18. A hard disk drive, comprising: ahousing comprising a base and a cover; at least one disk for storage ofdata within the housing; an actuator for reading and recording of thedata on the at least one disk; and an electrical connector comprising aflexible circuit embedded within and extending through an opening in thebase and providing electrical contact between electronics external tothe housing and one or more components within the hard disk drive,wherein the embedded flexible circuit comprises a labyrinth path throughthe base.
 19. A hard disk drive, comprising: a housing comprising a baseand a cover; at least one disk for storage of data within the housing;an actuator for reading and recording of the data on the at least onedisk; and an electrical connector comprising a flexible circuit embeddedwithin and extending through an opening in the base and providingelectrical contact between electronics external to the housing and oneor more components within the hard disk drive, wherein the embeddedflexible circuit comprises a serpentine path through the base.
 20. Ahard disk drive, comprising: a housing comprising a base and a cover; atleast one disk for storage of data within the housing; an actuator forreading and recording of the data on the at least one disk; and anelectrical connector comprising a flexible circuit extending through anopening in the base and providing electrical contact between electronicsexternal to the housing and one or more components within the hard diskdrive, wherein the opening extends essentially transversely from anexterior of the hard disk drive to approximately a midpoint of the basein an essentially linear manner, at which point the opening changesdirection, extending essentially longitudinally within the base beforechanging direction and exiting the base essentially transversely towardan interior of the hard disk drive.